The invention relates to a container made out of a flat material like paper, cardboard, etc., especially a parallelopipedal container for liquid made out of a composite of cardboard and plastic with a ridged-seam closure that extends along the upper surface and, continuing at each side, along fold-down triangles, which can be applied against the walls of the container, which can be demarcated by scores, which have scores slanting from the upper edge of the walls to the ridged-seam closure, and at least one of which is provided with a rip-out pouring aperture comprised of material-weakening lines.
A container of this type is known from German Patent 1 298 929 for example. To facilitate opening the container, it has a material-weakening line that is produced in the still flat packaging material in the form of a V-shaped or W-shaped perforated line and that extends at an angle to the base of the closure seam. The composites usually employed to manufacture aseptic containers, however, are made out of aluminum foil and tough plastic, and the weakening line is so difficult to separate that substantial force must be applied to rip out part of the head seam along the perforated line. It would of course basically be possible to make the perforated line deeper and hence facilitate separating it. This, however, is impossible in aseptic containers because the risk of leakage would be unacceptable.